KR20080053888A - Battery module - Google Patents

Abstract

A battery module is provided to reduce the effect of input of vibration thereon, including concentration of stress at the border between an electrode and a cell main body, and to realize a compact structure. A battery module comprises: a plurality of flat cells(101-108) each having a cell main body and at least one electrode tab; and a plurality of nipping plates(110). The cell main body comprises a power generating device sealed in a packaging member, and the electrode tab is electrically connected to the power generating device and protruded out from the cell main body. The flat cells are stacked on each other in such a manner that the electrode tabs are electrically connected to each other along the stacking direction. Among the nipping plates, nipping plates adjacent to each other along the stacking direction nip a part of the cell main body and electrode tab of one corresponding flat cell of the flat cells from two opposite sides of the one corresponding flat cell of the flat cells.

Description

Battery module {BATTERY MODULE}

<Cross Reference of Related Application>

This application is an application claiming the priority of Japanese Patent Application Laid-Open No. 2006-333693, filed December 11, 2006. The entire contents of the Japanese Laid-Open Patent Publication No. 2006-333693 are incorporated herein by reference.

The present invention relates to a battery module including a plurality of thin cells stacked on each other in a thickness direction.

A thin cell (cell) comprising a cell body consisting of a power generating element sealed to a laminated film or other package member, and a thin plate-shaped electrode electrically connected to the power generating element and configured to extend from the cell body to the outside. Techniques are known for. Japanese Laid-Open Patent Publication No. 2001-256934 discloses that thin cells are stacked in the thickness direction so as to obtain a battery module having a high output and a high capacity (that is, stacked on top of each other so that the stacking direction may correspond to the thickness direction). Disclosed is a battery module case electrically connected together.

In this regard, it will be apparent from this specification that there is a need for an improved battery module for those skilled in the art. The present invention can address this need in the art as well as address other needs apparent to those skilled in the art from this specification.

In the case where the battery module is installed in the vehicle as an example, it is necessary to make the gap between the thin cells as small as possible in order to form a smaller overall size of the battery module. Since the electrode of the thin cell has a thin plate shape, when the battery module is subjected to vibration, the electrode and the cell body vibrate separately. As a result, stress can be concentrated at the boundary between the electrode and the cell body. Due to this stress concentration, fatigue at the boundary may be caused, and the strength of the boundary may be lowered. Thus, there is a need for a battery cell structure that is less affected by vibration.

Accordingly, it is an object of the present invention to provide a battery module that can be manufactured in a small size without being easily affected by the input of vibration.

To achieve this object of the invention, a battery module comprises a plurality of flat cells and a plurality of nipping plates. Each flat cell has a cell body and at least one electrode tab. The cell body includes a power generating element sealed to the package member. The electrode tab is electrically connected to the power generating element and protrudes outward from the cell body. The flat cells are stacked on each other such that the electrode tabs are electrically connected in the stacking direction. In the stacking direction of the nipping plates, adjacent nipping plates follow the stacking direction from two opposite sides of the corresponding flattened cell of one of the flattened cells to a portion of the cell body and the electrode tab of the corresponding flattened cell of one of the flattened cells. Nip.

These objects, features, aspects, and advantages of the present invention and other objects, features, aspects, and advantages will become apparent to those skilled in the art from the following detailed description, which discloses a preferred embodiment of the present invention with reference to the accompanying drawings. .

According to the present invention, there is provided a battery module that can be manufactured in a small size without being easily affected by vibration.

DETAILED DESCRIPTION Hereinafter, selected embodiments of the present invention will be described with reference to the accompanying drawings. Those skilled in the art, the embodiments of the present invention presented below are not intended to limit the present invention to these embodiments merely by way of example only, the present invention is equivalent to the appended claims You will clearly see the limitations of water.

1 to 4, there is shown a battery module 50 according to an embodiment of the present invention. In more detail, Figure 1 is an overall perspective view of a battery module 50 according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the battery module 50 shown in FIG. 1. 3 is a perspective view of the cell unit 60 of the battery module 50, and is a perspective view showing a state in which the cell unit 60 is removed from the case 70 in which the cell unit 60 is incorporated. 4 is a perspective view of a plurality of thin cells 101 to 108 (flat cells) forming the cell unit 60. In the following description, the short side of the battery module 50 closer to the observer is called the "front side" and the farther side is called the "rear side". In addition, in the following description, the thin cells 101 to 108 are simply referred to as "cells".

As shown in FIGS. 1 to 4, the battery module 50 includes a cell unit 60 embedded in the case 70. In the illustrated embodiment of this invention, cell unit 60 comprises eight cells 101-108. The battery module 50 is arranged to be installed in a vehicle, for example, a car or a train, in which vibration is generated and transmitted to the cell unit 60.

Although not shown in the drawings, in order to be able to form a battery pack having desired current, voltage and capacity characteristics, any number of battery modules 50 may be stacked and connected together in series or in parallel. When several battery modules 50 are connected in series or in parallel, a suitable connecting member, for example a bus bar, is used. The battery module 50 is air cooled, and a collar is inserted between the battery modules 50 to enable the formation of an air gap when one or more battery modules 50 are stacked. This air gap serves as a cold air passage allowing cold air to flow through each battery module 50 to cool it. By cooling cold air to cool the battery module 50, the battery temperature can be lowered, and a decrease in characteristics such as charging efficiency can be suppressed.

The battery module 50 is a type of battery pack (ie, a battery having an assembly of battery units or single cells connected together) in that it includes several cells 101 to 108 electrically connected together. However, in the present description, the term "battery module" is used to refer to a base unit for assembling a battery pack, and a plurality of cells take the form of a unit stored in a case.

As shown in Figs. 1 and 2, the case 70 serves as a lid for sealing the box-shaped lower case 71 having the opening 71a and the opening 71a of the lower case 71. And an upper case 72. The edge portion 72a of the upper case 72 crimps around the edge of the surrounding wall 71b of the lower case 71 so as to seal the opening 71a of the lower case 71. Is formed. The lower case 71 and the upper case 72 are made of a relatively thin steel or aluminum sheet metal press-molded into a predetermined shape. The circumferential wall 71b has a plurality of vents 71g for allowing cold air to flow into the case 70.

As shown in Figs. 2 and 3, the cell unit 60 includes a cell group 100 (a plurality of flat cells), a plurality of plate spacers 110 (nipping plates), and an anode output terminal ( 140, a cathode output terminal 150, and a holder 180. The cell unit 60 also includes a voltage detecting terminal plate 160 (shown in detail in Figs. 12, 13A, 13B and 14A). The cell group 100 is composed of eight cells 101 to 108 stacked in the thickness direction and electrically connected in series. Each plate-shaped spacer 110 corresponds to a nipper plate used for stacking the cells 101 to 108. The voltage detecting terminal plate 160 is used to detect the voltage of each of the cells 101 to 108 (see FIG. 7A described below). The holder 180 is installed in the spacer 110 and is formed to hold the voltage detecting connector 170 (see FIGS. 18 to 20 described below). This connector 170 is connected to the voltmeter 172 via a harness 171 (see FIG. 18), and is connected to the voltage detecting terminal plate 160 in order to be able to detect the voltage of the cells 101 to 108. Electrically connected. The voltages of the cells 101-108 are detected to manage the charging and discharging of the battery module 50. The spacer 110 attached to the top surface of the top cell 108 is coated with a foamed material 116 as shown in FIG. Therefore, the nonuniformity of the height of the cell unit 60 is adjusted by the elastic deformation of the foam material 116.

As shown in FIG. 2, the positive output terminal 140 and the negative output terminal 150 are connected to the case 70 through several notches 71d and 71e formed in a part of the circumferential wall 71b of the lower case 71. Pass outside). The opening of the holder 180 disposed inside the case 70 faces the insertion opening 71f or notch formed in a part of the circumferential wall 71b. This insertion opening 71f allows the connector 170 to be inserted into the holder 180 from the outside of the case 70. In order to allow the bolt (not shown) to penetrate the four corner portions of the case 70, bolt holes 73 are provided in the four corner portions of the respective lower case 71 and the upper case 72, Bolt holes 111 are provided in two transverse edges of each spacer 110. As shown in FIG. 2, a sleeve 74 is inserted into the bolt hole 111 of each spacer 110.

The position of the spacer 110 is fixed relative to the case 70 by passing the bolt through the bolt hole 73 and the sleeve 74 of the lower case 71 and the upper case 72. Since the spacers 110 are attached to the cells 101 to 108, when the position of the spacers 110 is fixed, the positions of the cells 101 to 108 with respect to the case 70 can be determined.

The structure of eight cells 101 to 108 will now be described with reference to FIG. To make the explanation easier, the first cells 101, the second cells 102, and the third cells are arranged in order from the bottom to the top along the stacking directions (vertical directions in FIGS. 2 and 3). It is referred to as 103, fourth cell 104, fifth cell 105, sixth cell 106, seventh cell 107, and eighth cell 108. 4, the right side closer to the observer is the front side, and the left side farther from the observer is the rear side. In Figure 4, the bottommost first cell 101 is shown at the bottom left, and the top eighth cell 108 is shown at the top right.

Each of the first cell 101 to the eighth cell 108 includes a cell body 100b, a pair of first electrodes (anode and cathode) for connecting the cells 101 to 108 together, and voltage detection. And a second electrode for connecting to the terminal plate 160. 4, the first cell 101 to the eighth cell 108 are positive electrode tabs 101p, 102p, 103p, 104p, 105p, 106p, 107p, 108p and negative electrode tabs 101n, 102n, 103n, 104n, respectively. , 105n, 106n, 107n, 108n). The positive electrode tabs 101p to 108p and the negative electrode tabs 101n to 108n correspond to the first electrode. In contrast, the first to eighth cells 108 include electrode tabs 101v, 102v, 103v, 104v, 105v, 106v, 107v, and 108v respectively corresponding to the second electrode. The tabs 101v to 108v are disposed on one side of the anode side and the cathode side. For example, as shown in Fig. 4, the tab 101v of the first cell 101 is disposed on the same side as the negative electrode tab 101n. Further, the tabs 101v to 108v are smaller than the positive electrode tabs 101p to 108p and the negative electrode tabs 101n to 108n. In the following description of the illustrated embodiment, the positive electrode tabs 101p to 108p and the negative electrode tabs 101n to 108n corresponding to the first electrode are called "tabs 100t1" and the electrode tab corresponding to the second electrode. 101v to 108v is referred to as "tap 100t2". To call the electrode more generally without distinction between the first electrode and the second electrode, the term "tab 100t" is used.

In addition, in the description of the illustrated embodiment, the “electrode tab” is defined as a portion extending from the cell body 100b to the outside. In other words, the term “electrode tab” refers only to an electrode portion that can be recognized outside of the cell body 100b. In the case of thin cells in which one end of the thin electrode is directly connected to the power generating element and the other end extends out of the cell body, the “electrode tab” is an electrode portion, ie, a cell extending from the edge of the cell body to the other end of the electrode. It is an electrode part exposed outside the main body. Similarly, in the case of thin cells where one end of the thin electrode is connected to the power generating element via a conductive member and the other end extends out of the cell body, the “electrode tab” is moved from the edge of the cell body to the other end of the electrode. An extended electrode portion, that is, an electrode portion exposed from the outside of the cell body.

As shown in the box by the dashed line in FIG. 4, the eight cells 101-108 are divided into three separate subassemblies, namely the first subassembly 81, the second subassembly 82, and the third subassembly. It is assembled as the assembly 83. The first subassembly 81 is formed by stacking the second cell 102 on the top surface of the first cell 101 to connect the first cell 101 and the second cell 102 in series. The second subassembly 82 stacks the third cell 103, the fourth cell 104, and the fifth cell 105 on top surfaces of each other to form the third cell 103, the fourth cell 104, and the like. It is formed by connecting the fifth cell 105 in series together. The third subassembly 83 stacks the sixth cell 106, the seventh cell 107, and the eighth cell 108 on top surfaces of each other, such that the sixth cell 106, the seventh cell 107, and the like. Formed by connecting the eighth cell 108 together in series.

As shown in FIG. 4, the positive output terminal 140 is installed in the first subassembly 81, and the negative output terminal 150 is installed in the third subassembly 83. The first subassembly 81 and the second subassembly 82 are electrically connected together at all sides by bonding the negative electrode tab 102n of the first subassembly 81 to the positive electrode tab 103p of the second subassembly 82. Is connected. The second subassembly 82 and the third subassembly 83 are electrically connected together at the rear side by joining the negative electrode tab 105n of the second subassembly 82 to the positive electrode tab 106p of the third subassembly 83. Is connected. Thus, the first cell 101 to the eighth cell 108 are electrically connected in series. The second cell 102 of the first subassembly 81 is joined to the third cell 103 of the second subassembly 82, and is bonded to each other via a double-sided tape therebetween, and the second subassembly 82 is attached thereto. The fifth cell 105 is bonded to the sixth cell 106 of the third subassembly 83 and joined between them with a double-sided tape interposed therebetween.

As shown in Figs. 3 and 4, the positive output terminal 140 has a plate-shaped bus bar arranged to overlap the positive electrode tab 101p of the first cell 101, and at the end of the bus bar. And a resin cover 142 covering the provided terminal area. The negative output terminal 150 includes a plate-shaped bus bar arranged to overlap the negative electrode tab 108p of the eighth cell 108, and a resin cover 152 covering the terminal area provided at the end of the bus bar. ).

For example, a known method such as an ultrasonic welding method or a laser welding method includes a junction between each electrode tab 100t1, a junction between each electrode tab 100t2 and the voltage detecting terminal plate 160, an anode tab 101p and a busbar. And the junction between the negative electrode tab 108n and the busbar.

5 is an enlarged perspective view of the second cell 102 as one example of cells 101 to 108. FIG. 6A is a schematic cross-sectional view of a stacked cell, and FIG. 6B is a schematic cross-sectional view of a bipolar cell.

As shown in Fig. 5, the cell 102 is, for example, a flat lithium ion secondary battery having a cell body 100b, a positive electrode tab 102p and a negative electrode tab 102n. The cell body 100b includes a stacked power generating element 100e sealed in a package member 100a made of a laminated film or the like. The positive electrode tab 102p and the negative electrode tab 102n are thin and plate-like as shown in FIG. The positive electrode tab 102p and the negative electrode tab 102n are electrically connected to the power generating element 100e (a power storage element or a power supply element), and are disposed to lead to the outside of the cell body 100b. The positive electrode tab 102p and the negative electrode tab 102n extend from the short side (front side and back side) of the cell 102. In cells 101 to 108 (cells with stacked power generating elements 100e), in order to maintain the performance of the cells 101 to 108 by keeping the distance between the cells 101 to 108 constant, It is necessary to apply pressure to the device 100e in the stacking direction. Thus, the cells 101 to 108 are embedded in the case 70 to be pressed toward each other.

6A shows a first example cell 102 with stacked power generation elements 100e. In order to facilitate understanding of the present invention, the laminated structure of stacked cells 102 is schematically and exaggerated as shown in FIG. 6A. The power generating element 100e of the stacked cell 102 includes a plurality of anodes 301 and a plurality of cathodes 303 separated by a plurality of separators 302. Each anode 301 includes a current collector 301a having a pair of positive electrode active material layers 301b and 301c formed on both sides thereof. Each negative electrode 303 includes a current collector 303a having a pair of negative electrode active material layers 303b and 303c formed on both sides thereof. The insulator 302 is made of a mesh-like insulator and forms an electrolyte layer together with an electrolyte that fills the internal space of the stacked cell 102 surrounded by the package member 100a. The positive electrode active material layer 301b and the negative electrode active material layer 303c are alternately arranged, with an electrolyte layer disposed therebetween so as to face the electrolyte layer generally in parallel with each other, thereby generating a power generating element 100e ( Power storage element or power supply element).

The current collector 301a of the positive electrode 301 and the current collector 303a of the negative electrode 303 are welded to the positive electrode tab 102p and the negative electrode tab 102n, respectively. 6A, there are three anodes 301 and four cathodes 303 alternately stacked on top surfaces of each other and connected in parallel in a stacked cell 102.

The power generating element 100e is sealed with the package member 100a to form the cell body 100b of the cell 102. In the stacked cell 102 shown in Fig. 6A, the positive electrode tab 102p has a thin plate shape extending inside the cell body 100b and extending to the outside of the cell body 100b. The negative electrode tab 102n has a thin plate shape that extends inside the cell body 100b and extends to the outside of the cell body 100b.

FIG. 6B shows another structure cell 102 'disposed as a bipolar cell with stacked power generation elements 100e'. In order to facilitate understanding of the present invention, the stacked structure of stacked cells 102 'is schematically and exaggerated as shown in Figure 6b. The power generating element 100e 'of the bipolar cell 102' includes a plurality of bipolar electrodes 202 and a stack of a plurality of electrolyte layers 203 disposed alternately therebetween. Each bipolar electrode 202 includes a current collector 204 having a positive electrode active material layer 205 formed on one side and a negative electrode active material layer 206 formed on the other side. The positive electrode active material layer 205, the electrolyte layer 203 and the negative electrode active material layer 206 constitute a single cell layer 207. Insulation layers 208 are provided around the outer periphery of each single cell layer 207 for insulation to adjacent current collectors 204. The outermost current collector 204a on the top surface of the power generating element 100e 'in the figure only has a positive electrode active material layer 205, and the outermost on the bottom surface of the power generating element 100e' in the figure. The current collector 204b has only the negative electrode active material layer 206. The power generating element 100e 'is sealed with the package member 100a to form the cell body 100b. In the bipolar cell 102 'shown in FIG. 6B, the outermost current collector 204a having only the positive electrode active material layer 205 extends inside the cell body 100b and out of the cell body 100b. Subsequently, the sheet-shaped positive electrode tab 102p is formed. The outermost current collector 204b having only the negative electrode active material layer 206 forms a negative electrode tab 102n extending inside the cell body 100b and extending out of the cell body 100b.

In the illustrated embodiment, both the stacked cell 102 shown in FIG. 6A and the bipolar cell 102 'shown in FIG. 6B are shown as examples of the second cell 102. The type of cell 102 or 102 'may be selected according to the cell capacity and cell voltage required.

7A and 7B show how the front side of the cell 102 is retained by the spacer 110. 8 is a cross-sectional view taken along the line 8-8 of FIG. 7B. 9 is a plan view of the first cell 101 provided with the positive output terminal 140 and the spacer 110. 10A and 10B show how the positive output terminal 140 and the spacer 110 are attached to the front side of the first cell 101. FIG. 11 is a sectional view taken along line 11-11 of FIG. 10B. 12 is a perspective view showing an example of the spacer 110 (first spacer 121) together with the voltage detection terminal plate 160. 13A and 13B show how the voltage detecting terminal plate 160 is attached to the spacer 110. 14A is a plan view showing a spacer 110 to which a voltage detecting terminal plate 160 is attached. 14B is a cross sectional view taken along line 14B-14B in FIG. 14A.

Spacers 110 are used when the cells 101-108 are stacked together. When only the electrode tab 100t is squeezed or nipped between the spacers 110, a structure in which the cells 101 to 108 and the spacer 110 are connected only at the tab portion is formed. As a result, displacement due to vibration is concentrated at the boundary between the electrode tab 100t and the cell body 100b, and a phenomenon such as cracking may occur at the boundary.

Therefore, in the battery module 50 according to the illustrated embodiment, as shown in FIGS. 7A, 7B, and 8, the spacer 110 is formed in a plate shape, and the electrode tabs are formed from both surfaces along the stacking direction. 100t) and at least a portion of the cell body 100b of the cell 102 are configured and arranged to crimp or nipper (hold). In addition, the spacer 110 is made of an electrical insulating material at least on the surface facing the electrode tab 100t. 7A, 7B and 8, the entire spacer 110 is preferably made of an electrical insulation material. The material of the spacer 110 is not limited as long as it has sufficient strength and electrical insulation to compress and hold the electrode tab 100t and a part of the cell body 100b. For example, a resin material having electrical insulation can be used. A bolt hole 111 for inserting the sleeve 74 (see FIG. 2) is provided in each of the transverse (lengthwise) edge portions of the spacer 110 and passes from the top surface to the bottom surface of the spacer 110.

Since the tab 100t and a part of the cell body 100b are held by the spacer 110, an overlapping portion in which the spacer 110 and a part of the cell body 100b overlap is formed. Due to this overlap, the bending point formed due to the vibration is moved from the boundary between the electrode tab 100t and the cell body 100b to a position in the cell body 100b. As a result, the bending load applied to the electrode tab 100t is reduced. When the battery module 50 is vibrated, part of the cell body 100b and the electrode tab 100t vibrate together as a single unit, so that stress is concentrated at the boundary between the electrode tab 100t and the cell body 100b. Will not be. As a result, the fatigue life of the electrode tab 100t is improved, so that the durability of the battery module 50 can be improved. Even if the bending point due to the vibration is moved into the cell body 100b, since the cell body 100b is embedded in the package member 100a, fatigue failure is not caused, and thus rigidity greater than that of the electrode tab 100t against vibration is obtained. Will have Since a part of the cell body 100b and the electrode tab 100t are held by the spacer 110, the electrode tab (even if the gap between the cells 101 to 108, that is, the gap between the electrode tabs 100t, is small). Short circuit between 100t) can be prevented. As a result, the gap between the cells 101 to 108 can be made as small as possible, so that the overall size of the battery module 50 can also be made smaller. As a result, a battery module 50 can be provided which can be manufactured in a small size without being easily affected by vibration.

In the illustrated embodiment, the cells 101 to 108 are stacked such that the electrode tabs 100t overlap each other in the stacking direction. As a result, since the electrode tabs 100t can be directly connected together by ultrasonic welding or any other bonding method, there is no need for an additional bus bar or the like for connecting the electrode tabs 100t together. As a result, no additional structural parts are added to the electrode tab 100t, so that the electrode tab portion is lighter, which is advantageous for vibration.

It is necessary for the spacer 110 to insulate the electrode tabs 100t which are not connected together. Since the spacer 110 is coupled to the cell body 100b as described above, no additional structural parts are attached to the electrode tab 100t, which makes the electrode tab portion lighter, which is advantageous for vibration.

As shown in FIGS. 7A, 7B and 8, the spacer 110 is generally divided into two shapes including a first spacer 121 and a second spacer 122. The first spacer 121 is formed to be attached to the voltage detecting terminal plate 160. The second spacer 122 may not be attached to the voltage detecting terminal plate 160. The detailed structure of the first spacer 121 is shown in FIGS. 12 to 14.

As shown in Figs. 12-14, the first spacer 121 generally has several rectangular window-shaped openings 123, the openings of which extend from the top surface of the first spacer 121 to the bottom surface thereof. Through is penetrated in the lamination direction. Generally, a U-shaped portion 124 (notch) is provided in the longitudinal center portion of the first spacer 121. Two windowed openings 123 are generally disposed at the left and right sides of the U-shaped portion 124, respectively. A pair of protrusions 125 are each provided between the generally U-shaped portion 124 and the adjacent windowed opening 123. The electrode tab 100t held by the spacer 110 is generally aligned in the windowed opening 123 (see FIG. 7B). The first spacer 121 further includes a pair of retaining members 127, each of which has holes 126 as best shown in FIG. 14B.

As shown in FIG. 12, the voltage detecting terminal plate 160 is a unitary unitary member having a generally rectangular base 161 and a terminal portion 162 extending from the base 161. As shown in FIG. The through hole 163 is formed on the base 161 to be formed so that the protrusion 125 provided in the first spacer 121 is fitted. The base 161 is fixed to the first spacer 121 by fitting one of the protrusions 125 through the through hole 163 as shown in FIGS. 13B and 14. The base 161 is connected to electrode tabs 101v to 108v corresponding to the second electrode. The holding member 127 having the hole 126 allows the terminal portion 162 to be inserted therein. The retaining members 127 are respectively provided on both sides of the generally U-shaped portion 124 so as to be spaced apart from each other along the longitudinal direction of the first spacer 121. The hole 126 is formed along the longitudinal direction of the first spacer 121 (that is, the opening faces the longitudinal direction of the first spacer 121). The size of the hole 126 in the thickness direction of the terminal portion 162 is such that the terminal portion 162 is formed between the terminal portion 162 and the holding member 127 on both sides of the terminal portion 162 facing in the thickness direction. 162) (see FIG. 14B). The gap CL allows the terminal portion 162 to be held by the first spacer 121 to move in the stacking direction.

If the terminal portion 162 of the voltage detecting terminal plate 160 is fixed with respect to the spacer 110, the position and pitch of the terminal portion 162 in the stacking direction is when the cells 101 to 108 and the spacer 110 are stacked together. It is determined according to the position of the cells 101 to 108. As a result, fluctuations in the thickness magnitude (scattering) of the cells 101 to 108 and fluctuations in the thickness magnitude (scattering) of the spacer 110 result in an uneven position of the terminal portion 162 within the battery module 50 as a whole. Done. The connector 170 is provided with a plurality of connection terminals 173 (refer to FIG. 19, described in detail below) formed to be connected to the terminal portion 162 of the voltage detecting terminal plate 160, thereby providing a predetermined connection terminal 173. Is positioned. Therefore, if the position of the terminal portion 162 is uneven, insertion of the connector 170 becomes difficult, and if the connector 170 is forcibly inserted, it may cause a poor contact between the connecting terminal 173 and the terminal portion 162. Can be.

Thus, by forming the components to be held by the first spacer 121 (in a floating state) so that the terminal portion 162 can be moved in the stacking direction, variations in the thickness size of the cells 101 to 108 and Variation in the thickness size of the spacer 110 can be absorbed, so that the connecting operation of the connector 170 can be more easily achieved.

As shown in FIGS. 13A and 13B, when the voltage detecting terminal plate 160 is installed in the first spacer 121, the protrusion 125 of the first spacer 121 may have the through hole 163 of the base 161. The terminal portion 162 is inserted into the hole 126 of the holding member 127 by moving the voltage detecting terminal plate 160 in the longitudinal direction of the first spacer 121 until it fits therein. In this manner, the base 161 of the voltage detecting terminal plate 160 is fixed to the first spacer 121, and the terminal portion 162 of the voltage detecting terminal plate 160 is moved in the stacking direction. To be held by the first spacer 121. The voltage detecting terminal plate 160 may be installed at the first spacer 121 together with the base 161 at one side (left or right side) of the U-shaped portion 124. 13B and 14 show that the voltage detecting terminal plate 160 is disposed on the first spacer 121 such that the base 161 is disposed on the right side of the U-shaped portion 124 (that is, the right side in the perspective direction of FIGS. 13B and 14). The installed state is shown. On the other hand, FIGS. 7A and 7B show that the voltage detecting terminal plate 160 has a first spacer (1) so that the base 161 is disposed on the left side of the U-shaped portion 124 (that is, the left side in the perspective direction of FIGS. 7A and 7B). 121 is shown installed state.

As shown in FIG. 7A, the second spacer 122 includes a pair of ribs 128 disposed to overlap with the retaining member 127 of the first spacer 121.

The package member 100a is formed by joining together the outer edge portions of the pair of sheet members 100c to form flange portions 100d (joint portions) formed on each of the front and rear sides of the cell body 100b. It has a bag shape. The electrode tab 100t is formed so as to protrude outward from between the two sheet members 100c. The spacer 110 is formed to compress or nipper the flange portion 100d and the electrode tab 100t from both surfaces (upper and lower surfaces) in the stacking direction.

As shown in FIG. 7A, the battery module 50 includes the flange portions 100d of the respective cells 101 to 108 and the first spacer 121 and the second spacer 122 of each pair of spacers 110. ), Several coupling members 190 are arranged to engage. Coupling member 190 allows cells 101-108 to be positioned relative to spacer 110. In addition, when the battery module 50 is subjected to vibration, the vibration may be distributed into the two sheet members 100c in the flange portion 100d through the coupling member 190. As a result, the stress concentration phenomenon at the boundary between the electrode tab 100t and the cell body 100b is further suppressed, so that the fatigue life of the electrode tab 100t can be further improved.

Each coupling member 190 includes a through hole 191 penetrating through the flange portion 100d of each of the cells 101 to 108 in the stacking direction, and into a through hole 191 provided in the first spacer 121. It includes a fastening portion 192 is formed to fit. Since the through hole 191 is open in the flange portion 100d and does not penetrate the electrode tab 100t1, the size of the electrode tab 100t1 connects only one electrode tab 100t1 to another electrode tab 100t1. It can only be determined by the surface area needed to make it work. Thus, the electrode tab 100t1 need not be larger than the size required for the connection. Since the electrode tabs 100t1 can be made smaller, the size of each of the cells 101 to 108 can be made smaller, so that the entire battery module 50 can be made smaller.

The fastening part 192 is a pin formed in the first spacer 121 to protrude in the stacking direction. Fastening 192 is also referred to as embossment. Each first spacer 121 has two fastening portions 192, one of which is disposed near the longitudinal end of the first spacer 121. Each second spacer 122 has a pair of through holes 193 (fastening holes) arranged for the fastening portion 192 to be inserted.

After the fastening part 192 is penetrated through the through hole 191 and the through hole 193, the head part 194 is formed at the distal end of each of the fastening parts 192 by pressing the distal end. The head portion 194 serves to prevent the fastening portion 192 from escaping to the outside of the through hole 191 (that is, to keep the fastening portion 192 in the through hole 193), thereby providing a cell ( 101 to 108 and the spacer 110 are fixed together. By using only the fastening portion 192 of the first spacer 121 or the through hole 193 of the second spacer 122 and the fastening portion 192 of the first spacer 121, the coupling structure provided in the spacer 110 is Is formed.

More specifically, FIGS. 7A, 7B and 8 illustrate the coupling member 190 of the spacer 110 at the front side of the second cell 102. The fastening portion 192 of the first spacer 121 is inserted through the through hole 191 of the cell 102 and through the through hole 193 of the second spacer 122. Then, in order to be able to form the head portion 194 larger than the hole diameter of the through hole 191 of the cell 102 at least, the distal end (tip end) of the fastening portion 192 may be a head or an ultrasonic wave. It is compressed using (deformed). The head portion 194 prevents the fastening portion 192 from being detached from the through hole 191 of the cell 102, and the first spacer 121, the flange portion 100d of the cell 102, and the second spacer ( 122) to securely bond together.

On the other hand, as shown in FIGS. 9, 10A, 10B, and 11, at the front side of the first cell 101, the fastening portion 192 of the first spacer 121 is a flange portion of the cell 101. It penetrates through the through hole 191 formed in 100d. Then, the distal end of the fastening portion 192 is deformed to form the head portion 194. The head portion 194 prevents the fastening portion 192 from being detached from the through hole 191 of the cell 101, and fixes the first spacer 121 and the flange portion 100d of the cell 101 together. Play a role.

The coupling member 190 serves to position the cells 101 to 108 and the spacer 110 and to fix the cells 101 to 108 and the spacer 110 to each other. Since the same coupling member 190 is used for this position and fixing role, space is saved compared to the structure in which separate positioning members and fixing members are used. Thus, the battery module 50 can be made smaller. In addition, since the cells 101 to 108 and the spacer 110 are not separated, the cells 101 to 108 and the spacer 110 can be handled more easily, so that the stacking operation of the cells 101 to 108 is more effective. Can be easily achieved.

Each of the cells 101 to 108 has electrode tabs 100t2 (101v to 108v) for connecting to the respective voltage detection terminal plates 160, and electrode tabs 100t1 for connecting the cells 101 to 108 together ( 101p to 108p and 101n to 108n). The electrode tab 100t2 is an independent electrode tab separated from the electrode tab 100t1. Although vibration is transmitted to the voltage detecting terminal plate 160 through the connector 170, the vibration is not directly transmitted to the electrode tab 100t1 because the electrode tab 100t1 is an independent electrode tab separated from the electrode tab 100t2. As a result, durability of the electrode tab 100t1 can be improved.

One of the pair of spacers 110 (for example, the first spacer 121 or one of the cell bodies 100b of any one of the cells 101 to 108 that compresses and holds the electrode tab 100t) The second spacer 122 is shared as one of the other pair of spacers 110 that compresses and holds a portion of the other cell body 100b of the cells 101 to 108 and the electrode tab 100t. It is used. For example, the front side of the first cell 101 is the first spacer 121 attached to the first cell 101 and the other first spacer attached to the bottom of the second cell 102 (see FIG. 15). It is pressed and held between 121. In the present embodiment, the first spacer 121 attached to the second cell 102 compresses and holds a part of the cell body 100b and the negative electrode tab 102n of the second cell 102 while simultaneously holding the first spacer 121. A portion of the cell body 100b of the cell 101 and the positive electrode tab 101p are pressed and held. By sharing the spacers 110 in this manner, the gap between the electrode tabs 100t of the upper cell (eg, the second cell 102) and the electrode tabs of the lower cell (eg the first cell 101) ( The spacing between 100 t) can be reduced. As a result, the gap between the cells 101 to 108 can be formed as small as possible, so that the overall size of the battery module 50 can be made smaller.

The attachment structure of the connector 170 and the holder 180 to the battery module 50 will now be described in detail with reference to FIGS. 15 to 20.

FIG. 15 is a partial cross-sectional view of the rear side of the battery module 50 taken along line 15-15 of FIG. 16A is a perspective view of holder 180 holding connector 170 before holder 180 is attached to spacer 110. 16B is a perspective view of the holder 180 after the holder 180 is attached to the spacer 110. 17 is a front view of the holder 180 after the holder 180 is attached to the spacer 110. 18A is a plan view of the connector 170 before the connector 170 is inserted into the battery module 50. FIG. 18B is a plan view of the connector 170 after the connector 170 is inserted into the battery module 50. FIG. Figure 19 is a cross sectional view taken along the line 19-19 of Figure 18A. 20 is a sectional view taken along line 20-20 of FIG. 18B. The connector 170 is installed at the front side and the rear side of the battery module 50, but only the rear side of the battery module 50 is shown in Figs.

As described above, the terminal portion 162 of the voltage detecting terminal plate 160 is floatably held by the spacer 110 in order to be able to absorb the variation in the thickness of the cell. Since the connecting terminal 173 (see Figs. 19 and 20) of the connector 170 is disposed at a predetermined position, the connecting operation of the connector 170 positions the terminal portion 162 according to the position of the connecting terminal 173. Can be more easily achieved.

Thus, as shown in FIG. 15, the battery module 50 according to the illustrated embodiment includes a limiting member 195 that serves to position the terminal portion 162 in the stacking direction. Accordingly, the connector 170 having the connecting terminal 173 can be connected to the terminal portion 162 whose position in the stacking direction is defined by the limiting member 195.

As shown in Figs. 15 and 16A, the limiting member 195 includes a holder 180 provided in the spacer 110 and several slits 181 formed in the holder 180. The holder 180 is formed and disposed to hold the connector 170. The slits 181 are arranged such that a portion of each terminal portion 162 can be inserted into the corresponding slits 181. Holder 180 is inserted into an insertion opening formed by generally U-shaped portion 124 of spacer 110. The slit 181 is formed on the side corresponding to the distal end of the holder 180 when the holder 180 is inserted. The slit 181 is formed at a position corresponding to the position of the connecting terminal 173 (Fig. 19). The holder 180 further includes several tong-shaped members 182 (coupling members) provided on the outer facing side of the holder 180. The tongs-shaped member 182 is formed to be fastened to each of the several fastening holes 112 formed in the spacer 110. When the holder 180 is press-fitted such that the forceps-shaped member 182 is engaged with the fastening hole 112 of the spacer 110, the holder 180 is fixedly attached to the spacer 110. Since the terminal portion 162 of the voltage detecting terminal plate 160 is floatably held by the spacer 110, when the terminal portion 162 is inserted into each slit 181 as shown in Figs. 18A and 19, The position of the terminal portion 162 is adjusted to a position corresponding to the position of the connection terminal 173 of the connector 170.

As described above, the battery module 50 includes a case 70 in which the cell group 100, the spacer 110, and the holder 180 are incorporated. The case 70 has an insertion opening 71f formed to allow the connector 170 to be inserted into the holder 180 from the outside of the case 70. Referring to Fig. 17, the insertion opening 71f is shown by the dashed line. As shown in Figs. 16A and 16B, the holder 180 further includes several stoppers 183 abutting on the inner side of the wall surrounding the insertion opening 71f. The stopper 183 is in contact with the inner side of the wall, so that even if the connector 170 is separated out of the holder 180 after the insertion of the connector 170, the holder 180 is not separated out of the insertion opening 71f. do.

18B and 20, when the connector 170 is connected to the battery module 50, the terminal portion 162 and the connection terminal 173 of the voltage detecting terminal plate 160 are easily connected together. Since the position of the terminal portion 162 is determined according to the position of the connecting terminal 173, the connecting operation of the connector can be achieved relatively easily.

21A and 21B are schematic cross-sectional views showing a first example and a second example of the spacer 110 material according to the above-described embodiment.

As shown in FIG. 21A, the spacer 110 may be manufactured from the elastic member 113. The stresses formed on the electrode tab 100t and the cell body 100b may be dissipated and lowered by the elastic member 113, and thus durability of the electrode tab 100t may be improved. The elastic member 113 may also serve to cushion the stepped contour present at the boundary between the electrode tab 100t and the cell body 100b. Examples of the material that can be used for the elastic member 113 include chloroprene rubber (CR), butyl rubber (IIR), natural rubber (NR), butadiene rubber (BR) and styrenebutadiene rubber (SBR). It is not limited to this. It is preferable to use the elastic member 113 having a relatively high friction coefficient. The electrode tab 100t and the cell body 100b may be maintained by the friction force generated by the compression of the elastic member 113. The friction coefficient of the elastic member 113 changes depending on the pressing method and the temperature of the elastic member 113, but the movement of the electrode tab 100t and the cell body 100b is caused by the frictional force using a friction coefficient of about 2.0 or more. May be limited.

In addition, as shown in FIG. 21B, the spacer 110 may be manufactured by stacking the elastic member 113 and the inelastic member 114. By adopting the laminated structure including the elastic member 113 layer and the non-elastic member 114 layer, the ratio of the elastic member 113 to the non-elastic member 114 is changed to thereby compress the compressive force of the spacer 110. It can be set to any predetermined intensity. In the spacer 110 adopting such a structure, it is preferable to manufacture a part of the cell body 100b and the surface of the spacer 110 facing the electrode tab 100t with the elastic member 113, and thus sufficient compressive force. In addition to ensuring the acquisition of the vibration, the vibration transmitted to the electrode tab 100t and the cell body 100b can be reduced, so that durability of the electrode tab 100t can be improved. The above materials can be used for the elastic member 113. Examples of the inelastic material member 114 include, but are not limited to, polycarbonate (PC) or other resin material having a lower elasticity than the elastic material 13 described above.

The spacer 110 having the laminated structure including the elastic member 113 layer and the inelastic member 114 layer is not limited to the two-layer structure shown in Fig. 21B. For example, a three-layer structure in which one layer of inelastic member 114 is interposed between two layers of elastic member 113 may be employed. In another possible structure, the surface of the non-elastic member 114 is coated with the elastic member 113 to form a film of the elastic member 113 on the surface of the non-elastic member 114 to form the spacer 110. ).

Thus, according to the battery module 50 of the illustrated embodiment of the present invention, when the battery module 50 is vibrated, at least a part of the electrode tab 100t and each cell body 100b vibrates as an integrated unit. Therefore, stress is not concentrated at the boundary portion between the electrode tab 100t and the cell body 100b. As a result, the fatigue life of the electrode tab 100t is improved and the durability of the battery module 50 is improved.

General interpretation of the term

In determining the scope of the present invention, the term "comprising" and its derivatives, as used herein, specify, but not specify, the presence of the specified functionality, member, part, group, unit, and / or step. It is an unrestricted term that does not exclude the presence of functional parts, members, parts, groups, monoliths and / or steps. This also applies to terms with similar meanings, such as, for example, "including", "instrument", and derivatives thereof. In addition, the terms "part", "region", "portion", "member" or "element" may have the dual meaning of a single member or a plurality of members when used alone.

Although only selected embodiments of the present invention have been selected and described, it will be apparent to those skilled in the art that various changes and modifications can be made in the present invention without departing from the scope of the invention as set forth in the appended claims. You will be able to see clearly. For example, the size, shape, position or orientation of the various various components can be changed as desired. Parts shown to be directly connected to or in contact with each other may have intermediate structures disposed therebetween. The function of one member can be performed in two ways, and vice versa. The structure and function of one embodiment can be applied to another embodiment. Not all advantages need to be present at the same time in a particular embodiment. All features distinct from the prior art, alone or in combination with other features, should be considered as separate additional inventions by the applicant, with further additional inventions including structural and / or functional concepts implemented by such features. Should be considered. Accordingly, the foregoing description of the embodiments according to the present invention is presented for illustrative purposes only, and is not intended to limit the invention, which is defined by the appended claims and their equivalents.

Referring now to the description of the accompanying drawings, which form a part of this specification,

1 is an overall perspective view of a battery module according to an embodiment of the present invention.

2 is an exploded perspective view of the battery module shown in FIG. 1 in accordance with an exemplary embodiment of the present invention;

3 is a perspective view showing a cell unit of the battery module shown in FIGS. 1 and 2, wherein the cell unit is removed from the case of the battery module according to the illustrated embodiment of the present invention.

4 is a perspective view of a plurality of thin cells forming the cell unit of the battery module shown in FIG. 3 in accordance with an illustrated embodiment of the present invention.

FIG. 5 is an enlarged perspective view of one of the thin cells shown in FIG. 4 in accordance with an illustrated embodiment of the present invention. FIG.

6A is a simplified cross-sectional view of a first example of a thin cell of a battery module (cell) according to the illustrated embodiment;

6B is a sectional view schematically showing a cross section of a second example of the thin cell of the battery module (cell) according to the embodiment described above.

FIG. 7A is an enlarged partial exploded view showing the front side of the thin cell shown in FIG. 5 coupled to a spacer in accordance with an illustrated embodiment of the present invention; FIG.

FIG. 7B is an enlarged partial exploded view showing a state in which the front side of the thin cell shown in FIG. 7A is coupled to the spacer according to the illustrated embodiment of the present invention; FIG.

FIG. 8 is a partial cross-sectional view taken along the line 8-8 of FIG. 7B with the front side of the thin cell coupled to the spacer in accordance with the illustrated embodiment of the present invention. FIG.

9 is a plan view of one of the thin cells shown in FIG. 5 with spacers and anodic output terminals installed in the thin cell in accordance with an illustrated embodiment of the present invention;

10A is an enlarged partial exploded view showing the front side of the thin cell shown in FIG. 9 coupled to a spacer and a positive output terminal in accordance with an illustrated embodiment of the present invention;

Fig. 10B is an enlarged partial exploded view showing a state in which the front side of the thin cell shown in Fig. 10A is coupled to a spacer and a positive output terminal according to an exemplary embodiment of the present invention.

FIG. 11 is a partial cross sectional view taken along line 11-11 of FIG. 10B of a front side of a thin cell coupled to a spacer and a positive output terminal according to an illustrated embodiment of the present invention; FIG.

Fig. 12 is an exploded perspective view of a spacer (first spacer) and a voltage detecting terminal plate according to the illustrated embodiment of the present invention.

FIG. 13A is a perspective view of the spacer shown in FIG. 12 showing a state before the voltage detecting terminal plate is attached to the spacer according to the illustrated embodiment of the present invention; FIG.

Fig. 13B is a perspective view of the spacer shown in Figs. 12 and 13A showing a state after the voltage detecting terminal plate is attached to the spacer according to the illustrated embodiment of the present invention;

14A is a plan view of the spacer shown in FIGS. 12, 13A, and 13B showing a state in which a voltage detecting terminal plate is attached to the spacer according to the illustrated embodiment of the present invention;

14B is a cross sectional view taken along lines 14B-14B of FIG. 14A of a spacer in accordance with an illustrated embodiment of the present invention.

Figure 15 is a partial cross sectional view taken along line 15-15 of Figure 3 of the cell unit shown in Figure 3 in accordance with an exemplary embodiment of the present invention.

Fig. 16A is a partial perspective view showing a part of the cell unit and the holder shown in Figs. 3 and 15, before the holder holding the connector is attached to the spacer according to the illustrated embodiment of the present invention.

Fig. 16B is a partial perspective view showing a part of a cell unit and a holder in a state after the holder is attached to the spacer according to the illustrated embodiment of the present invention.

Fig. 17 is a partial front view of the holder and the cell unit shown in Figs. 16A and 16B after the holder is attached to the spacer according to the illustrated embodiment of the present invention.

FIG. 18A is a partial plan view of the battery module shown in FIG. 1 with the connector before the connector is inserted into the battery module in accordance with the illustrated embodiment of the present invention; FIG.

FIG. 18B is a partial plan view of the battery module shown in FIGS. 1 and 18A after the connector has been inserted into the battery module according to the illustrated embodiment of the present invention.

FIG. 19 is a partial cross sectional view taken along line 19-19 of FIG. 18A of a battery module and connector according to an illustrated embodiment of the present invention;

20 is a partial cross-sectional view taken along line 20-20 of FIG. 18B of a battery module and connector according to an illustrated embodiment of the present invention.

FIG. 21A is a simplified partial cross-sectional view of the battery module and the spacer showing an exemplary first member of the spacer according to the embodiment described above. FIG.

FIG. 21B is a simplified partial cross-sectional view of the battery module and spacer showing an exemplary second member of the spacer according to the embodiment described above. FIG.

<Explanation of symbols for the main parts of the drawings>

50: battery module 60: cell unit

70: cases 101 to 108: cell

110: spacer 140: positive output terminal

150: negative output terminal 160: voltage detection terminal plate

170: voltage detection connector 180: holder

Claims (19)

A plurality of flat cells each having a cell body and at least one electrode tab, Including a plurality of nippers, The cell body includes a power generating element sealed in a package member, wherein the electrode tabs are electrically connected to the power generating element and protrude outward from the cell body, and the electrode tabs are stacked on each other so as to be electrically connected in a stacking direction. , A portion of the cell body and the electrode of the corresponding flat cell of one of the planar cells from two opposite sides of the corresponding flat cell of one of the planar cells along the stacking direction of the nipping plates adjacent to the stacking direction of the nippers Battery module for nipping the tabs. The battery module of claim 1, wherein the nipping plate is made of an electrical insulation material. 2. The package of claim 1, wherein each of the package members of the cell body has a bag shape formed by a pair of sheet members joined together to form a junction disposed at an outer edge of the package member, each of the electrode tabs. Of the package members protrude outwards between the sheet members of the corresponding wrapper member, wherein the nipping plate is joined from the opposite sides of the corresponding flattened cell of one of the flattened cells along the stacking direction to the electrode tab and the electrode tab. Battery module that nippers. 4. The battery module of claim 3, wherein at least one of the adjacent nipping plates of the nippers has a coupling structure coupled with the junction of the package member of the corresponding flat cell of one of the flattened cells. The coupling structure of claim 4, wherein the coupling structure comprises a pin formed on one of the adjacent nipping plates among the nipping plates, the pin having a through hole provided at a junction of a package member of the corresponding flat cell of one of the flat cells. Penetrating battery module. 6. The battery module according to claim 5, wherein the pin has a head portion formed at the distal end of the pin to hold the pin in the through hole. 6. The battery module of claim 5, wherein the coupling structure further comprises a fastening hole formed in the other one of the adjacent nipping plates, wherein the fastening hole is fastened to the pin after the pin passes through the through hole. The battery module according to claim 7, wherein the pin has a head portion formed at the distal end of the pin to hold the pin in the fastening hole. The battery module of claim 1, wherein a part of each nipper plate facing the electrode tab is made of an elastic material. The battery module of claim 9, wherein each of the nippers is manufactured by stacking an elastic material layer and an inelastic material layer. The portion of each nipper plate facing the corresponding electrode tab of one of the electrode tabs and the portion of each nipper plate facing the cell body of the corresponding flat cell of one of the flat cells is an elastic material. Battery module manufactured by. The method of claim 1, wherein each of the electrode tabs is configured to detect a voltage of a first electrode tab connecting one of the flat cells to an adjacent one of the flat cells and a corresponding flat cell of one of the flat cells. A battery module comprising a second electrode tab used. The battery module of claim 12, wherein the first electrode tab and the second electrode tab are separate independent electrode tabs. The terminal of claim 13, wherein at least one of the nippers comprises a voltage detecting terminal plate having a base and a terminal portion, the base electrically connected to a second electrode of the corresponding flat cell of one of the flat cells. The battery module is freely movable in the stacking direction. 15. The battery module of claim 14, further comprising a holder attached to the nipping plate to couple a voltage detection connector thereto. The battery module according to claim 15, wherein the holder includes a limiting member for limiting the position of the voltage detecting terminal plate in the stacking direction. The battery module of claim 16, wherein the limiting member of the holder includes a slit formed in the holder. 18. The apparatus of claim 17, further comprising a case containing the flat cell, the nipping plate, and a holder, the case having an insertion opening for inserting a voltage detection connector into the holder from outside of the case, wherein the holder is A battery module having a stopper in contact with an inner side of a wall surface of a case surrounding an insertion opening. An energy storage means for storing electrical energy in which the electrode tab protrudes outward from a corresponding cell body of one of the cell bodies stacked on each other so that the electrode tabs can be electrically connected in a stacking direction; And nipping means for nipping the electrode tab and the cell body of the flat cell from opposite sides of the flat cell along the stacking direction.

Images